Typhoid fever imported from Mexico to Switzerland. Studies on R factor mediated chloramphenicol resistance

Abstract

SUMMARYA case of typhoid fever caused bySalmonella typhioccurred in Geneva. The patient was probably infected in Mexico City. The strain isolated from this patient corresponds with the description of the MexicanS. typhistrain, since it is a degraded Vi-strain resistant to chloramphenicol, streptomycin, sulphonamides and tetracyclines. It carried anfi−transferable R factor with a CSSuT resistance pattern. It can be accepted that this case forms part of the Mexican outbreak of chloramphenicol-resistant typhoid fever which has already been observed in visitors to Mexico from England and the United States.

The problem and implications of chloramphenicol resistance in the typhoid bacillus

“…In a recent report (Anderson & Smith, 1972) we described a chloramphenicol-resistant strain of the typhoid bacillus that caused an enormous outbreak of typhoid fever (> 10,000 cases) in Mexico in 1972-3. A number of foreign visitors to that country were infected: at least 52 Americans, two British and one Swiss (Anderson & Smith, 1972;Waldvogel & Pitton, 1973;Cohen, 1973).…”

How multidrug resistance in typhoid fever affects treatment options

“…A moderate level of resistance and a trend of increasing MIC to chloramphenicol was reported in 1959–1961 in an Indian study . Resistance was observed in several other studies in the late 1960s . A large outbreak in 1972 in Mexico caused by a chloramphenicol‐resistant strain was alarming because of the large number of affected people (approximately 10,000).…”

“…13 Cases of typhoid acquired in Mexico with a similar resistance pattern were spread worldwide and observed in British and Swedish travelers. 10,12 The other interesting feature of this notable outbreak was an observed increase in resistance to ampicillin. 11 In the late 1970s, as the R factor increasingly conferred resistance to chloramphenicol, sulfonamides, tetracycline, and streptomycin, the alternative therapy of ampicillin and SXT was found to be effective.…”

“…The characteristic feature of the outbreak strain was its resistance to multiple antibiotics, including chloramphenicol, tetracycline, streptomycin, and the sulfonamides, which was caused by a genetic element—referred to at the time as the R factor —that was transferrable to Escherichia coli . Cases of typhoid acquired in Mexico with a similar resistance pattern were spread worldwide and observed in British and Swedish travelers …”

“…9 Resistance was observed in several other studies in the late 1960s. [10][11][12] A large outbreak in 1972 in Mexico caused by a chloramphenicol-resistant strain was alarming 11 because of the large number of affected people (approximately 10,000). The characteristic feature of the outbreak strain was its resistance to multiple antibiotics, including chloramphenicol, tetracycline, streptomycin, and the sulfonamides, which was caused by a genetic element-referred to at the time as the R factor-that was transferrable to Escherichia coli.…”